The study will enroll patients 18 years old or older who present to the hospital within twelve (12) hours of the onset of chest pain and who had ST segment elevation >1 mm in two contiguous limb leads or ST segment elevation >2 mm in two consecutive precordial leads or new onset of left bundle branch block (LBBB) in a twelve lead electrocardiogram and for whom the decision was made to be taken to the cath lab to perform angioplasty of the coronary vessels.